Bob Parker ESR Meters

[Per Hansson]

Re: Bob Parker ESR Meters

Assembled my MK2 ESR meter now, it's working fine, right at the first try also

Included some pics of it almost complete...

The test probes as was already said above do not work too well though, gonna buy a new pair at Elfa, need a pair for my multimeter anyway because they have also given up :/

Will also buy 2x 1N5404 diodes to put on the testleads to protect the meter from charged caps... Anything else I could add to make it even more safe?

And thanks Bob.P for joining the forum and designing the ESR meter for us crazy fools

[Per Hansson]

Re: Bob Parker ESR Meters

Just a thought to my post above, what if I also put 5w resistors after the diodes; should not that make the capacitor dissipate it's charge slowly and nicley while at the same time protecting the ESR meter?

Because the diode only approach sounds a bit dangerous if I connect it to a really big charged cap, I think bad stuff will happen

[Bob Parker]

Re: Bob Parker ESR Meters

Assembled my MK2 ESR meter now, it's working fine, right at the first try also

Included some pics of it almost complete...

The test probes as was already said above do not work too well though, gonna buy a new pair at Elfa, need a pair for my multimeter anyway because they have also given up :/

Will also buy 2x 1N5404 diodes to put on the testleads to protect the meter from charged caps... Anything else I could add to make it even more safe?

And thanks Bob.P for joining the forum and designing the ESR meter for us crazy fools

Hi Per,
You've built it very well. Congratulations that now you've got a Mk2 ESR meter!

In fact the crazy fool I designed the ESR for was ME. I thought it was so useful that I'd make the design public. Of course I'm very happy that lots of other crazy fools (and some sensible people!) are using it too.

So far I have not heard of anyone damaging an ESR meter after installing the big protection diodes. But if you connect it to a big charged high voltage capacitor, it will burn the tips off your new probes.

[Bob Parker]

Re: Bob Parker ESR Meters

Just a thought to my post above, what if I also put 5w resistors after the diodes; should not that make the capacitor dissipate it's charge slowly and nicley while at the same time protecting the ESR meter?

Because the diode only approach sounds a bit dangerous if I connect it to a really big charged cap, I think bad stuff will happen

The meter can only zero out test lead resistance of 0.99 ohms or less. This is a function of the design. You can't put resistors in series with the test leads. If you are really worried about connecting it to charged high voltage capacitors, you could put an inline fast-acting fuse in one of the test leads. The combined resistance of the fuse and test leads will need to be less than 0.99 ohms, so the choice of fuse will be more determined by that limitation than its current rating.

When I designed the meter, I never imagined that so many people would connect it to big charged high voltage capacitors, so I didn't allow for this to happen and only gave it protection up to about 50V.

[Per Hansson]

Re: Bob Parker ESR Meters

Thanks for the info Bob P, saw on your site the link to the Anatek DSESRSavr

http://www.anatekcorp.com/testequipment/dsesrsavr.htm

How does that thing work? To me it looked like just two big diodes and two resisitors plus the other two gigantic things I don't know what they are (capacitors?)

So I thought I could build something similar myself...

[Bob Parker]

Re: Bob Parker ESR Meters

Thanks for the info Bob P, saw on your site the link to the Anatek DSESRSavr

http://www.anatekcorp.com/testequipment/dsesrsavr.htm

How does that thing work? To me it looked like just two big diodes and two resisitors plus the other two gigantic things I don't know what they are (capacitors?)

So I thought I could build something similar myself...

It's a patented device. I've tried it and it protects the meter very well. However it slightly reduces the accuracy and increases the test lead resistance, and takes up space in the case. I'm not sure if it will fit in the Mk2 meter case. I'd suggest that you contact Anatek and buy one if it will fit; they don't cost very much.

[Topcat]

Re: Bob Parker ESR Meters

Do I get one for free???

[Bob Parker]

Re: Bob Parker ESR Meters

Do I get one for free???

A protector or an ESR meter? Unfortunately I don't have any of either of those things.

PS: I'm not a guru - just a technician who needed my own ESR meter so bad that I had to design one.

[starfury1]

Re: Bob Parker ESR Meters

Hi all

I thought I should mention this
(I don't think it has been mentioned)

If you use the meter near a monitor or TV that is going it will probably give spurious readings

So please make sure you are not near one when using it.

Not sure how bad with a TFT but probably ditto for them too

To get an idea,
try it for your selfs and at a few feet distance too.

It is mentioned in the notes somewhere or was it on Bobs site probably both.

This is something to beware of and its something you can easily forget too,
as we tend to have a computer or 2 close to our work bench.


The other thing is you might want to
get into the habit of discharging Higher voltage caps as a matter of course for your own safety
as much as for the meters.

When you get bitten by a cap sitting at 350 Volts DC you will know what I mean

Cheers

[Per Hansson]

Re: Bob Parker ESR Meters

The other thing is you might want to
get into the habit of discharging Higher voltage caps as a matter of course for your own safety
as much as for the meters.

When you get bitten by a cap sitting at 350 Volts DC you will know what I mean

Look what I found in the mail



I also got the testleads, they where not kiddin though, with testleads it's really only the leads, no cables!
Meh, guess I'm keeping the postal office busy atleast
Ordered some nice gold plated cables, also managed to order only one diode when I was fully aware I needed two!
Meh, see my blog post to see what all the whine is about today

[Per Hansson]

Re: Bob Parker ESR Meters

There, got cables now too

Just to make sure, is this the way the safety diodes are supposed to be installed? (the two vertical things being the wires going to the test lead sockets)

[Bob Parker]

Re: Bob Parker ESR Meters

There, got cables now too

Just to make sure, is this the way the safety diodes are supposed to be installed? (the two vertical things being the wires going to the test lead sockets)

Yes, that is correct.

[tazwegion]

Re: Bob Parker ESR Meters

The values placed on the MKII silk screening were a little confusing @ first for a novice such as myself... I mean 100R??? equates to what exactly? thankfully the included guide contained a helpful schematic (see inset)

Sadly... this is as far as I've got with the kit as my (former) faithful 25w iron has fizzled out, dunno' about everyone else... but I figured the 'other' 40w iron I have may be a little too 'heavy duty' for such a delicate undertaking

[Bob Parker]

Re: Bob Parker ESR Meters

The values placed on the MKII silk screening were a little confusing @ first for a novice such as myself... I mean 100R??? equates to what exactly? thankfully the included guide contained a helpful schematic (see inset)

Sadly... this is as far as I've got with the kit as my (former) faithful 25w iron has fizzled out, dunno' about everyone else... but I figured the 'other' 40w iron I have may be a little too 'heavy duty' for such a delicate undertaking

Please don't try to use a non-temperature-controlled 40W iron to build the meter. It's sure to burn component pads off the board and do other damage. When I designed it, I thought only experienced repair technicians with soldering stations would be building (and using) it. [Whimper].

[tazwegion]

Re: Bob Parker ESR Meters

I really had no intention of using the 40w iron, as I said it's too heavy duty for this delicate application, I generally only use the 40w on automotive jobs

Having the 25w burn out like it did is kinda' a blessing in disguise, as now I'll be able to purchase something significantly better, I mean when you consider it came with a DSE kit package I purchased more than 10 years ago... it's been productive

Thankfully the symbol on the silk screening combined with the photos & schematic provided in the guide booklet steered me in the right direction... BTW have no fear I'm not out to butcher your kit, it's only useful to me functional

[gdement]

Re: Bob Parker ESR Meters

Yeah, using a 40w iron is kind of rough. That was what I used, and I burned a few pads along the way. You have to move pretty fast for it to work, a little too fast for me to handle it sometimes. If the iron is there more than a couple seconds it'll fry.

[Bob Parker]

Re: Bob Parker ESR Meters

I really had no intention of using the 40w iron, as I said it's too heavy duty for this delicate application, I generally only use the 40w on automotive jobs

Having the 25w burn out like it did is kinda' a blessing in disguise, as now I'll be able to purchase something significantly better, I mean when you consider it came with a DSE kit package I purchased more than 10 years ago... it's been productive

Thankfully the symbol on the silk screening combined with the photos & schematic provided in the guide booklet steered me in the right direction... BTW have no fear I'm not out to butcher your kit, it's only useful to me functional

Whew... thanks for that. I've been supporting that kit since early 1996 and I've seen some real disasters caused by huge overheated soldering irons. I was hoping this wouldn't become the latest one.

[tazwegion]

Re: Bob Parker ESR Meters

Whew... thanks for that. I've been supporting that kit since early 1996 and I've seen some real disasters caused by huge overheated soldering irons. I was hoping this wouldn't become the latest one.

No worries, I've actually been weighing up my choices between a basic 25w Scope, a DSE (entry level) soldering station & a 13w 'Goot' pencil iron

[Bob Parker]

Re: Bob Parker ESR Meters

No worries, I've actually been weighing up my choices between a basic 25w Scope, a DSE (entry level) soldering station & a 13w 'Goot' pencil iron

I've briefly used one of the basic DSE soldering stations (with a little meter showing the temperature) and I thought it was pretty good.
It's always hazardous soldering PCBs with an uncontrolled iron because they tend to get awfully hot and de-laminate the copper foil. But a temperature controlled one operating at around 350C generally does the job very nicely.

[tazwegion]

Re: Bob Parker ESR Meters

Unfortunately, I missed the sale on that particular version T2200 (meter), but I did land it's little brother T1976 (minus meter), BTW thanks for the pointer(s) always appreciated

The 17w ~ 25w hobbist irons are quite nice IMHO, but their tips don't make fine/detailed soldering easy by any means... but I digress